Update PluginDataParam type definitions to include text label and pro…

[veeting]

We have identified that PluginDataParam has a few missing type definitions in janus.d.ts

• text
• label as optional
• protocol as optional

NOTE:

janus.js is either using text or data which is confusing. The html demos are only referring to text.
Thus, we have decided to not add data and add text as optional to avoid breaking any other app.

[lminiero]

janus.js is either using text or data which is confusing. The html demos are only referring to text.
Thus, we have decided to not add data and add text as optional to avoid breaking any other app.

I'd rather both are kept in there, with the idea only data will remain someday. text is legacy from when we only supported text data, which is not the case anymore: we support binary data too. The fact that demos only refer to that is simply a conseguence of those legacy assumptions.

[lminiero]

Thanks for the fix, merging!